Engineering Drawing Made Easy - By Atul Saxena

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ENGINEERING DR AWING MADE EASY

FOR ENGINEERING AND ARCHITECTURE (MODULE –I-CHAPTER-I) BY ATUL SAXENA B.E (STRUCTURES ) AIV, A.M.I.E. CHARTERED ENGINE ER

STUDENT MEMB ER THE INDIAN INSTITUTE OF ARCHITECTS NAVI MUMB AI 1

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Forward This book is written for helping students appearing for Architectural Drawing Part –I examinations organized by The Indian Institute of Architects. Entire Topics are presented in a teach your self style. Students appearing for under graduate engineering classes will also find it equally useful. My sincere thanks and regards to all known and unknown sources from where knowledge came. All readers’ feedback is welcome on [email protected]. Atul Saxena B.E.(Structures) AIV, A.M.I.E. (Civil), Chartered Engineer Consulting Structural Engineer ©Atul Saxena,Lucknow 2008 Price: FREE for online Viewing 2

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Contents Module-I Lesson 1:: Introduction…………….. Lesson 2:: Scales……………………. Lesson 3::Projection of Lines……… Lesson 4::Projection of Solids……… Lesson 5::Intersection of Surfaces…… Module: II Lesson 6:: Orthographic Projections……. Lesson 7::Isometric Projections…………. Lesson 8::Perspective Drawing…………. 3

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MODULE - I Lesson: 1 INTRODUCTION 1.1Understanding The questi on Paper Pattern(Revised Scheme 2004) In architectural drawing Section A questions are asked from Module A Each question is of 25 Marks. You have to attempt any two questions out of three. In section B questions are asked from Module-II. Each question contains 50 marks. Students are advised to practice module 2 very well to score good marks. Out of 3 questions 2 questions have to be attempted. Total time for solving question paper is 4hours.Special Emphasis should be given to neatness.Read the data given in problem carefully and write it neatly on drawing Sheet. Also write what is required or asked in order to avoid confusion.

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1.2 Definition:: Engineering Drawing/Graphics/Architectural drawing is the medium of communication between Architects/Engineers & work force on site of construction or any other engineering activity. ***************** *************************** 1.3How to Draw ☻Every question consists of 3 parts. ☻Each part should be clearly drawn & mentioned as directed under: 1) Given data: 2H Pencil with medium Pressure 2) Construction by 3H pencil 3) Answer by H Pencil

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1.3Notes on Types Of Lines Used In Architectural Drawing:: Types of lines used in architectural drawing are listed as under: 1) Outline/Principal Line 2) Hidden Lines 3) Centre Line or axis 4) Cutting Plane or Section Plane 5) Short Break line 6) Long Break line 7) Hatching Line 7

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8) Dimension Line 9) Construction/Extension Line

**Please refer figure on next page to have a clear understanding on types of lines used in Architectural/Engineering Drawing. Sufficient practice is required to make your drawing look impressive to examiner

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Figure: 1.1 Types Of lines used in Drawing

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Test your Underst anding; 1) How can you define Architectural Drawing? Elaborate your answer with examples. 2) List out Types of lines used in Architectural Drawing and draw them on drawing sheet.

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ENGINEERING DR AWING MADE EASY FOR ENGINEERING AND ARCHITECTURE (MODULE –I-Lesson-II-SCALES) BY ATUL SAXENA B.E (STRUCTURES ) AIV, A.M.I.E. CHARTERED ENGINE ER

STUDENT MEMBER THE INDIAN INSTITUTE OF ARCHITECTS. NAVI MUMBAI (INDIA) 12

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Forward This book is written for helping students appearing for Architectural Drawing Part –I examinations organized by The Indian Institute of Architects. Entire Topics are presented in a teach your self style. Students appearing for under graduate engineering classes will also find it equally useful. My sincere thanks and regards to all known and unknown sources from where knowledge came. All readers’ feedback is welcome. Atul Saxena Lucknow B.E.(Structures) 2008 AIV, A.M.I.E. (Civil), Chartered Engineer Consulting Structural Engineer ©Atul Saxena Price: FREE for online Viewing for limited Period

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Contents Module-I Lesson 1:: Introduction…………….. Lesson 2:: Scales……………………. Lesson 3::Projection of Lines……… Lesson 4::Projection of Solids……… Lesson 5::Intersection of Surfaces…… Module: II Lesson 6:: Orthographic Projections……. Lesson 7::Isometric Projections…………. Lesson 8::Perspective Drawing………….

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Lesson 2 SCALES · · · · · · · ·

Getting Started Enlarging Scales Reducing Scales Representative Fraction(RF) Types Of Scales Questions From AIIA Exams Solved Problems Test Your Underst anding

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Getting Started: Before going ahead we should know the fact that the entire real world objects need to be either enlarged or reduced to appropriate scale either enlarging or reducing. Enlarging Scale: When the small objects of real world are represented on greater scale on drawing sheet or paper. Example: Details of bolts shall be drawn on larger scale. Reducing Scale: When real world objects are drawn on lesser scale than actual then the scale is called reducing. Example: The map of a town shall be drawn on a reducing scale. Representative Fraction (RF) RF= Length of Drawing Actual Length

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Understanding Scales Better: If a length of 1000metre (1 KM) is represented by 1 mm RF =1/1000X1000=1/1000000 If 1 cm length represents 5m of actual length then RF =1/500 Types Of Scales: Frequently used architectural/engineering scales may be classified as under: 1) Plain Scale 2) Diagonal Scale 3) Comparative Scale 4) Vernier Scale 5) Scale of Chords.

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For solving questions on scales a clear concept of unit conversion is a must. Some of most commonly used units in problems on scales are listed with conversions for ready reference. Unit conversion 10MM 1CM 10Cm 1Decimeter(DM) 10DECIMETER 1METER 10METER 1DECAMETER( 1DAM) 10DECAMETERS 1HECTOMETER 10HETOMETER 1KM 1 HECTARE 10000SQUARE METRES 1 ACRE 4046.825 SQUARE METRES ***************************************

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Plain scales: It is the simplest type of scale. Single unit or two units and its subdivision are represented by i t. Method Of Plain Scale Construction: I. RF Calculation II. Calculation Of Length Of Scale (LS). Draw a line accordingly as per length of scale calculated. III. Length should be divided equal ly into no of parts. IV. Each part represents greater di vision unit. V. Further subdivide the first part which will represent the second uni t or first unit fractions.

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VI. Put zeros at the end of first division. Number the units on right side of the zero and subdivisions on LHS of zero.

VII. Name the scale and write the RF below the scale with units. Diagonal Scales: Digonal scales are most suitable for measuring distance as minimum as 0.1 mm. These are also used when distance to be measured is in three units for example: 1Km- 200m-50cm

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Method Of Construction Of Diagonal Scale: I .Draw any line PQ. II. Draw perpendicular. Join all the points to obtain a right angle triangle PQR. Divide QR into 10 equal parts and number them from 1 to 10.from theorem of similar triangles it is evident that like sides in a similar triangle are proportionate. Refer to figure on next page.

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Comparative Scales: Comparative Scales are scales having RF but graduated in different units. On a map if dist ance is shown in KM & meters it is possible to show it easily in mm

and cm by use of this scale. They can be drawn separately or one over ot her. Scale Of Chords: Scale of chord is very helpful in measuring angles with out help of protector. Method Of Construction: I. Draw AB & erect perpendicular at B. II. With AB radius draw arc with centre B cutting AB at C.With same radius cut arc from ‘C’ as centre, cutting at D. 24

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III. Divide AB into six equal parts by Trial & error method. With same distance divide arc AC into 18 equal parts. With centre A & radius =cut point on the arc draw the arc as shown in figure below. Write 0-90 on the arc AC and also on line AB. IV. It can measure minimum up to 5Degrees. Scale of Chords is shown on next page. Students are advised to make sufficient practice of dividing lines into equal parts.

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DEC-2005 Q.1. (A) Draw a line 600 meters on the scale of 1. 1:2000 2. 1:4000 3. 1:10000 4. 1:20000 (B) Draw a plane of 18000 Sq.m in area with same scale mentioned in A. Hint: 1. On scale of 1:2000 1 mm =2000 mm Hence 600m (600000mm) =600000/2000=300mm or 30cm

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Draw a line of 300mm or 30 cm. 2. On scale of 1:4000 1mm= 4000mm Hence600m= 600000/4000=150mm or 15cm Draw a line of 15 cm. 3. On scale of 1:10000 1mm = 10000 mm. Hence 600m=600000/10000=60mm=6cm Draw a line 6cm long. 4. On scale of 1:20000 ;1mm =20000mm Hence 600m=600000/20000=30mm=3cm Draw a line 3cm long. (B). √18000=134.164 say 134.2m will be one side of square. This required can be drawn to required scale similarly as above example. In Dec2004,Dec2005,June2006 problems on enlargement of scales have been asked which are very simple to draw and not worth any further mention here .Students are advised to practice these problems on their own on similar lines as above solved problem. Problems on diagonal scales are being frequently asked from last 3-4 examinations

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and these can be easily solved on basis of solved examples in preceding sections Dec 2008 Draw a diagonal scale of 1:5 and long enough to measure up to 40centimeters. Explain step wise construction of scale.and show a

measurement of 31.2 cm on this scale.(25marks)

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***Previous year question paper may be obtained from AIIA Office in Mumbai on against payment by post/courier. Hint: RF =1/5

Length of Scale=RF X Maximum distance to be measured =1/5X40=8cm Draw a line 8cm long and divide it in 4 equal parts each part represents 10 cm. Measure 30 cm on plane scale. Measure 1 cm on sub scale on LHS which is divided in 10 equal parts. Finally measure .2cm on diagonal scale. This problem is similar to solved problem 1 on preceding pages. Only data is changed. Note: Similar problem was asked in June 2008 on Diagonal scale. All types of problems on all types of scales have been presented here. Students are advised to practice these solved problems on drawing sheet. 31

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Upon sufficient practice they can easily solve all problems on scales very quickly and accurately. All problems of previous examination can be solved easily on basis of solved problems in next article. *************************************

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Construct a scale of RF 1/60 read meter and decimeter and long enough to measure up to 6meter. Mark on it a distance of 5.4metre. Solution:

RF=1/60 Length Of scale=RF X Max. distance =1/60X6X100=10cm=100mm

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Construction Procedure: I Draw a line 100 mm long and divide it into 6 equal parts II Divide first part into 10 equal parts. One division =1 decimeter. III.Finally mark the distance 5.4 meter with dark pencil. IV. Print RF below scale Problem 2. An actual distance of 4 Km is shown by a line 8cm on the map. Draw a plane scale reading in KM .Mark on t his scale following distances: i) 5.7Km ii) 3Km-3Hm iii) 220Dm .The scale should be long enough to measure up to 8 km.

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Solution;

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Construction Procedure: RF Calculation: R.F= Distance on Map Actual Distance =

8/4X1000X100=1/50000 LS= 1/50000X800000 =16 cm E

Draw a line 160 mm long and divide it into 8 equal parts.

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Divide first part into 10 equal parts. Each parts represents 1 decameter.

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Mark the distance with dark pencil and write RF below scale. 37

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Important Problem 3: Distance between Bombay and Pune is 180 Km .A passenger train covers this distance in 4 hours. Construct a scale to measure the distance train covers in single minute.RF of scale is 1/20000.Find the distance covered by train in 36 minutes. Assume that train travels along a straight path Solution: Distance covered in 4 hours= 180Km Hence distance covered in 1 min =180/ 4 X 1/60=.75 Km This can be obtained by dividing 3 km distance in 4 parts or 6Km distance in 8 parts. Hence distance traveled in 36 minutes =180/4X36/60=27Km

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LS = Max distance to measured X RF As distance to be measured is 27 km taking max distance to be measured as 30 km for sake of simplicity in drafting drawing. LS= 1/200000X3000000 = 15 cm=150mm Construction: E

Draw a line 150mm long and divide it into 5 equal parts

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Divide first part into eight equal parts. Each parts represents 1.5 Km and also 1min.

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Mark the distance traveled in 1 min and 36 min as shown in fig.

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Write RF below the scale.

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Problem 4. The distance between two cities is 300 Km.It is represented on road map by a line 6 cm. Find RF of the scale. Construct a diagonal scale to show hundred of Km tens of km; and sufficient enough to read max. Distance of 700 Km. Indicate on the scale following distances: E

AB=526 Km

CD=528 KM Solution:Rf=Distance on Map = Actual Distance =6X (1/300) X (1/1000) X (1X100). RF= 1/5000000 Max. Distance to be measured = 700Km LS= (1/5000000) X (700) X1000X100 =14 Cm=140mm E

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Construction: 1Draw a line 140mm long and divide it into 7 equal parts. 2. Divide first part into 10 equal parts. Put labels on the parts as shown in fig. 3. Draw vertical lines from these 10 parts.With help of divider divide these lines into 10 parts. 4. Join the diagonals as shown. i.e. join 0 with top of 10. Similarly join other remaining parts. 5. Show given distances. 6. Write RF below the scale

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Problem 5. The distance between two cities is 156 Kms.They are shown 156 mm apart on road map.Draw a diagonal scale.Draw a diagonal scale with this RF to measure up to 200 KM and show a distance of a)109Km b)168 Hectometer Solution: R.F=Distance on Map Actual Distance =(156)/(156X1000X1000) =1/1000000 LS =( 1/1000000)X200X1000X100 =20cms=200mm Construction:1)Draw a line 200mm Long 2) Divide first part into 10equal parts and number them as shown. 3) Draw vertical lines from these 10 parts. 4) Divide these lines into 10 equal parts with help of divider. 5) Join Diagonal i.e. 0 with top of 10. Similarly join other remaining parts as shown. 45

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6) Show distance as asked in question 7) Write RF below scale. Measurement: 1)109Km=100Km+8Km+1Km(5X2Hm) 2)168Hm=0Km+16Km+8Hm(4X2Hm)

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Problem.6)The distance between two cities is 120Km.A passenger train covers this distance in 4 hours.Construct a scale to measure a distance to measure distance covered by train in a single minute and up to 1 hour. The scale is 1/200,000. Show distance covered in 36 minutes. Solution:RF = 1/200,000 Distance covd. In 1 hour= 120/4=30Km LS= RF X Max distance to be measured. = (1/200,000) X30X1000X100 = 15cm = 150mm. Construction: 1) Draw two parallel lines 15 cm long. 2) Divide lines into 3 equal parts each part representing 10 Km. Divide other line into 6 equal part each representing 10 min. 3) Show 36 min as shown. 4) Measure distance traveled. 5) Print RF of Scale below

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Vernier Scale: Vernier Scale is often used in place of diagonal scale and it can read up to small unit accurately.A vernier scale consist of a primary scale fully divided into minor divisions and a vernier having graduations derived from primary scale. A part of plane scale shown in fig represents length AO= 10cm. If we divide this length into 10 equal parts. Each part represents 1cm.Now to divide this smaller part into 10equal part to get measurement in mm is very difficult. Let us take length BO = 10+1=11Cm.Now divide 11cm distance into 10equal parts. Each part=1.1Cm=11mm.The difference between one

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part on main scale AO and one division on vernier BO will be 1.1-1=0.1cm or 1mm. Similarly the difference between two parts on AO and two on BO will be 0.2 cm or 2 mm.From this description the fundamentals of vernier scale construction can be generally stated as follows: If a length of n units divided into n equal parts then each part = (n+1) n =1+1/n units. Now a length = n+1 of these units divided into n equal parts. Then each part =n+1 n= 1+1/n units. The difference one each part and former part is: n+1 -n = 1/n unit. n n Similarly difference between 2 parts from each will be 2/n units.

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Problem. 7.The distance OF 500 meter is represented by 15cm line in drawing. Construct a vernier scale to read up to 600m. Mark on it distance of 549 m.

RF=Distance on Drawing Actual Distance = 15 500X100 = 3 100000 54

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LS= RF X Max. Distance LS= (3/100000) X600X100 = 18cm = 180mm Construction method: Draw a line 180mm long and divide it into 6 equal parts each part will represent 10cm.Set off length to 11 parts to the left and above the primary scale divide it into 11 equal parts. Forming a vernier represents 100mm.Print RF below scale. Measurement =Main scale +Vernier Scal e 549 = 494+55 Problem 8 A water tank of 27 cum size was represented on drawing as 216 cum size. Construct a vernier to measure up to 5 m. Show on it following lengths. A) 3.95m B) 0.27m C) 0.042m 55

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Solution: Volume of Tank On drawing = Actual volume. 216 3 cm 3 = 273m3 6cm = 3m RF = Length of Drawing Actual Length =6 3X 100 = 1/50 LS = RF X Max Length to be measured =1/50X5X100 =10cm Construction Method : E

Draw a line 10cm long ;divide into 5 equal parts ;each represents 1 metre.

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Divide first part into 10 equal part to show decimeter.

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Set off 11 parts on to the left and above primary scale and divide it into 10 equal parts. Each part represents 10cm. 57

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Print RF below scale

Measurement : Distance = Main Scale + vernier scale 1) 3.95m = 3.4m +0.55 m (55Cm) 2) 0.27m =0.5m +0.77m(77Cm) 3) 0.042m= Not possible to measure

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Prob.9Draw angle 350,800,1450 with help of scale of chords.

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a) Construct a line AB = x b)With centre B and radius x; draw an arc ACD. c)Measure 350 on scale of chord and cut it on the Arc ACD at point p with centre A. Join pB. Angle Abp = 350. d) Measure 800 on scale of chords and cut it on the arc at point q with centre A. Join qb. Angle ABq=800. e) Erect Perpendicular at A. cutting arc ACD at C. Measure 550(1450-900) on scale of chords and cut on it the arc ACD from centre C cutting at point r. Join Br. Angle Abr = 90+55 = 1450

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